I agree that the use of infoset rather than syntax is a bizarre choice
from an interoperability point of view but I don't see it as any worse
than the fact that the spec allows people to use standardized XML syntax
over proprietary protocols that will not be able to speak to each other.
Even SOAP running over open protocols is not compatible if different
people choose different protocols. A message sent over SOAP over SMTP is
not going to get to a SOAP/HTTP recipient except through a specialized
intermediary.
The SOAP specification consistently emphasizes surface-level flexibility
("do your own thing") over interoperability ("we'll tell you what to
do."). Wire level interoperability comes not from the specification
itself but by the N*M testing done on SoapBuilders, with Microsoft's
toolkit behaviour having a particularly strong weighting in importance.
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XML, Web Services Architecture, REST Architectural Style
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